1. Field of the Invention
The present invention relates to a projector apparatus which optically enlarges an image on a small display device having a liquid crystal panel, a cathode ray tube, or the like and projects the enlarged image on a screen to display the enlarged image. More particularly, the invention relates to a projector apparatus in which a light-emitting tube (light source) emitting illumination light can be effectively cooled.
2. Description of the Related Art
For example, projector apparatus of the above-described type according to the related art include projectors as disclosed in JP-A-2005-10505 (Patent Document 1). Patent Document 1 discloses an illumination apparatus in which clouding of glass, deformation of a light-emitting tube, reduction of the life of the light-emitting tube, and degradation of image quality can be prevented. The patent document 1 also discloses a projector having such an illumination device. The illumination device disclosed in Patent Document 1 has a light-emitting tube emitting illumination light, and the illumination device is to be used in a projector which can project images with the projector housing turned upside down. The projector is also characterized in that it includes a cooling device for cooling the light-emitting tube by a downward air flow in either of a situation in which an image is projected with the projector housing in a normal setup and a situation in which an image is projected with the projector housing turned upside down from the normal setup.
Effects expected from the projector disclosed in Patent Document 1 include an advantageous mode of cooling in which a top half of the light-emitting tube can be sufficiently cooled while preventing a bottom half of the light-emitting tube from being over-cooled (paragraph [0019] of Patent Document 1).